Lighting in offices is usually provided as a combination of different types of lighting systems. For example, fluorescent lighting is installed in a ceiling as general illumination of the office, desktop lamps serve for providing individual task lighting for individuals working on a desk, and halogen spots are positioned on the ceiling or on the wall for providing spot lighting for pictures hanging at the wall. In this way, light can be provided having several different illumination profiles, such as functional as well as decorative purposes, and/or as general illumination as well as individual task lighting. Most types of lighting systems are one-time installed, fixed installations, but recently also one-time installed, adjustable installations have been proposed, allowing adjusting the illumination profile. Some individual, standalone lamps may be adjustable, such as the desktop lamp.
An example of such a standalone adjustable lamp is described in US patent application US 2003/0193802 A1. This document describes a diode light source system for stage, theatre and architectural lighting including a plurality of separate flat panels for mounting a plurality of light emitting diodes emitting a plurality of diode light beams to a common focus area. A housing containing the panels has a centre base portion and a circular rim defining a housing aperture aligned with a circular rim plane having a rim plane centre arranged transverse to an axis aligned with the centre base portion. A screw arrangement positions the panels at a plurality of selected positions where each panel is oriented at a selected angle relative to the axis, and the grouped diodes emit diode light beams transverse to each separate panel.